net: bcmgenet: Do not suspend PHY if Wake-on-LAN is enabled

Suspending the PHY would be putting it in a low power state where it
may no longer allow us to do Wake-on-LAN.

Fixes: cc013fb4 ("net: bcmgenet: correctly suspend and resume PHY device")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>